Tarpaulin cover

ABSTRACT

An improved tarpaulin cover system for truck bodies wherein intermediate portions of the tarpaulin between its ends are slidably secured for longitudinal movement with respect to the truck body on a pair of semi-rigid, non-movable linear fixed support members, the semi-rigid support members being separate and distinct from the movable drive cable by which the lead bow and tarpaulin are moved. The system is adaptable to both truck box and flat deck trailer type bodies. The system according to the present invention makes the tarpaulin system more wind resistant than conventional movable tarpaulin cover systems and provides more safety by maintaining the tarpaulin in position even if the drive cable breaks.

BACKGROUND OF THE INVENTION

This invention relates to an improved tarpaulin cover system for open-top truck bodies.

Movable tarpaulin cover systems for truck boxes or trailers of the type including a floor, front wall and a pair of upright side walls and/or flatbed trailers are known in the prior art. See, for example Cramaro Canadian Patent No. 995,714 issued Aug. 24, 1976 and Biancale Canadian Patent No. 1,094,129 issued Jan. 20, 1981. In such systems, one end of a tarpaulin to cover the truck body is anchored to the front wall. A plurality of intermediate support bows extend in parallel fashion from side-to-side transversely across the truck body, the bows being secured at spaced locations to the tarpaulin. The ends of the intermediate bows are slidably secured on a movable cable for longitudinal movement with respect to the truck body. A lead bow extending parallel to the intermediate bows from side-to-side transversely across the truck body is secured to the free end of the tarpaulin. The ends of this bow are secured to the movable cable for movement therewith longitudinally with respect to the truck body. When the cable is moved in one direction, the lead bow and free end of the tarpaulin are drawn longitudinally to the back end of the truck body and the intermediate bows and tarpaulin are drawn proportionately rearwardly as required to covering the truck body. When the cable is moved in the opposite direction, the lead bow, intermediate bows and tarpaulin are retracted to the front end of the truck body to open position. In Biancale Canadian Patent No. 1,094,129, a single drive cable is provided with a pair of horizontal reaches of the cable extending along parallel to and above each of the upper edges of the box, the cable being in the form of a closed or endless loop mounted on pulleys attached to the truck box. A pair of the runs of the cable cross over each other from one side of the box to another in a region disposed below the upper edges of the box so that movement of the cable along its path causes each of the pair of horizontal reaches to move in the same direction relative to the upper edges of the box to effect movement of the tarpaulin. The cable is moved by means of a winch.

In Cramaro Canadian Patent No. 995,714, a pair of cables, one on each side of the truck box are provided, each cable providing one of the pair of horizontal reaches of the cable extending along parallel to and above each of the upper edges of the box. The two cables are simultaneously winched for movement.

Such conventional prior art systems have presented several problems in operation. Firstly, such systems have not reacted well to the winds generated during normal motion of the truck on which they have been installed. Such wind has caused the bows to bend out of position and cause wear and tear on the cable. As a result, the tarpaulin has required strapping to the truck body to keep it taut and in position. As well there is additional wear on the cable since the intermediate bows have their ends slidably secured to it.

Another danger exists if the drive cable on such a conventional system breaks. The tarpaulin and bow will then be released from the truck resulting in a potentially hazardous situation particularly if the truck is in transit.

U.S. Pat. No. 3,231,305 of Beckman issued Jan. 25, 1966 describes and illustrates a collapsible cover assembly for vehicles, on which the ends of the bows are mounted on sleeves which travel horizontally on a pair of rigid, tubular tracks mounted on either side of the truck body. While such a system may be suitable for a pick-up truck or the like, for which it was intended, it would not be suitable for a larger truck trailer. On larger truck trailer there would inevitably be a sag in the track which would make the sleeves very difficult or impossible to move. As well, such a system could not withstand the normal abuse to which a cargo trailer for a truck would be subject in loading and unloading, where inevitably such a track would occasionally be hit by the loading vehicle and bent or damaged, again further interfering with proper sliding of the sleeves.

Other patents of general background interest relating to tarpaulin cover systems for trucks are described and illustrated in Pickering et al U.S. Pat. No. 4,032,186 issued June 28, 1977 and Rodrigue Canadian Patent No. 1,107,790 issued Aug. 25, 1981.

It is an object of the present invention to provide an improved tarpaulin cover system for trucks which to some extent avoids or minimizes the problems of conventional systems with wind. It is a further object of the present invention to provide such a tarpaulin cover system for use on commerical truck bodies such as flat deck trailers and truck boxes, which system has increased safety.

SUMMARY OF THE INVENTION

In accordance with the present invention there is provided an improved arrangement for a tarpaulin cover system for open-top bodies of trucks or trailers, the system being of the type comprising a tarpaulin to cover the body, one end of which is anchored to the front of the body, a plurality of intermediate bows to extend in parallel fashion from side-to-side transversely across the body, the bows secured at spaced locations to the tarpaulin to support it, a bow support system on which the ends of the intermediate bows are slidably secured for longitudinal movement with respect to the body and a lead bow extending parallel to the intermediate bows from side-to-side transversely across the body, the bow secured to the free end of the tarpaulin and the ends of this bow secured to the bow support system for movement therewith longitudinally with respect to the body. Movement of the lead bow in one direction draws the free end of the tarpaulin longitudinally to the back end of the body and draws the intermediate bows and tarpaulin associated with each proportionately rearwardly as required, to a position covering the body. Movement of the lead bow in the other direction retracts the tarpaulin and intermediate bows to the front end of the body where the tarpaulin is in open position. The improvement is characterized by a pair of linear, semi-rigid fixed bow support members, one longitudinally extending from front to back along the body on each side thereof. The ends of the intermediate bows are slidably mounted on the semi-rigid bow support members for longitudinal movement. A separate, movable drive cable is provided with portions longitudinally extending from front to back along the body on each side thereof parallel to the corresponding bow support member. These portions of the drive cable are simultaneously movable from front to back or back to front, as required, along each side of the body. The ends of the lead bow are secured to corresponding portions of the drive cable on each side of the body so that movement of the portions of the drive cable as required will move the lead bow, tarpaulin and intermediate bows to covering position or to open position with respect to the body.

In a preferred embodiment of the present invention, the semi-rigid bow support members are cables immovably secured on each side of the body. The system according to the present invention may be applied to either box-type truck or trailer bodies or to flat deck trailers.

Since the tarpaulin cover system of the present invention has intermediate bows secured on semi-rigid bow support members which are separate and independent from the movable drive cable means, greater wind resistance of the system is provided. Where the semi-rigid bow support is a cable, it can be made more rigid than the drive cable to counter the effects of wind. As well, the system in accordance with the present invention provides significantly improved safety. For example, the intermediate bow supports do not slide on the drive cable and cause it to wear as in conventional systems. As well, if the drive cable of the present invention were to break during transit, the intermediate bows, being secured to the semi-rigid bow support members and not to the drive cable, would remain in position.

BRIEF DESCRIPTION OF THE DRAWINGS

These and other objects and advantages of the invention will become apparent upon reading the following detailed description and upon referring to the drawings in which:

FIG. 1 is a perspective view of a box-type truck body, on which a tarpaulin cover system in accordance with the present invention has been mounted;

FIG. 2 is a schematic view of the movable cable system of the tarpaulin cover system of FIG. 1;

FIG. 3 is an enlarged detail perspective view of a portion of the tarpaulin cover system of FIG. 1;

FIG. 4 is a partial side view of a further embodiment of the tarpaulin cover system in accordance with the present invention as applied to a flat deck trailer; and

FIG. 5 is a partial rear view of the system of FIG. 4.

While the invention will be described in conjunction with example embodiments, it will be understood that it is not intended to limit the invention to such embodiments. On the contrary, it is intended to cover all alternatives, modifications and equivalents as may be included within the spirit and scope of the invention as defined by the appended claims.

DETAILED DESCRIPTION OF THE INVENTION

In the drawings, similar features have been given similar reference numerals.

Turning to FIG. 1 there is illustrated a tarpaulin cover system in accordance with the present invention mounted on a truck body of the type including a floor 4, a front wall 6 and a pair of upright side walls 8, each of which define a generally horizontal upper edge 10. A tarpaulin 12 is supported by intermediate bows 14 and a lead bow 16 in a manner which will be described in more detail hereinafter. One end of tarpaulin 12 is secured to the top of front wall 6. Lead bow 16 is secured to the tarpaulin near its other, free end and intermediate bows 14 are secured at spaced, regular intervals to tarpaulin 12 as illustrated.

The ends 18 of intermediate bows 14 are slidably secured to, and supported by, a pair of cables 20, for example by means of sleeves or connectors 21 secured thereto, one cable immovably secured, in horizontal orientation, near the upper edge 10 of each of side walls 8 to act as a linear, non-moving semi-rigid bow support member. (A single cable 20 extending along each of these sides and across the front wall 16 may alternatively be used.)

A second, drive cable 22 is installed with a pair of horizontal reaches 24 extending along parallel to cables 20. In the illustrated embodiment, a single cable as described and illustrated in Biancale Canadian Patent No. 1,094,129 is used, with the cable being mounted on a plurality of pulleys 26 attached to the truck body to support the runs of the cable and arranged with a pair of runs of the cable crossing over each other from one side of the truck body to the other below or at the front as illustrated in FIG. 2, so that movement of the cable along its path causes horizontal reaches 24 to move in the same direction relative to the upper edges 10. An appropriate winch means 28 is provided for movement of drive cable 22. Lower ends 30 of lead bow 16 are fixedly secured, by an appropriate sleeve or connector and securing means 31, on either side of the truck body, to drive cable 22 as illustrated.

Alternatively, instead of a single drive cable 22, a pair of drive cables 22 (as described and illustrated in Cramaro Canadian Patent No. 995,714) operated by winch 28 may be mounted, one near the upper edge 10 of each of side walls 8, again with a horizontal run 24 of each of these cables extending parallel to corresponding cable 20 on each side wall 8.

Ends 30 of lead bow 16 are fixedly secured to drive cable 22 as illustrated in FIG. 3 to move at a similar speed a similar amount in a similar direction on each side of the truck body when the drive cable is activated by winch 28. It is preferred that lower ends 30 also each be slidably mounted on the corresponding cable 20, for example by an appropriate sleeve 36 secured thereto. This double sleeve arrangement at the ends 30 of lead bow 16 assists in restricting the pivoting movement of bow 16 in operation and during movement of the vehicle in which the system is mounted. When the drive cable 22 is moved in one direction, lead bow 16 and the free end of tarpaulin 12 are drawn to the back of the truck body. At the same time, each intermediate bow 14 and the associated portion of tarpaulin 12 to which it is secured slide rearwardly on cables 20 an amount dictated by the location across tarpaulin 12 at which each intermediate bow is secured. By moving the drive cable 22 in the opposite direction, lead bow 16, intermediate bows 14 and tarpaulin 12 are retracted towards front wall 6 to expose floor 4 of the truck body for loading purposes. This system enables the bows and tarpaulin to be "floated" on the semi-rigid cables 20, thereby requiring no rail or the like to support and guide the bows on upper edges 10.

Turning to FIGS. 4 and 5, a tarpaulin cover system 2 particularly adapted for flat deck trailers having a floor or platform 4 with side edges 40 is illustrated. In this embodiment, intermediate bows 14 are of inverted U-shape with vertical arms 42 extending downwardly from a transverse, bridging central portion (not illustrated). A series of rollers 46 are mounted to arms 42 at similar distances from ends 18 of the bows, as illustrated, these rollers movably supported on horizontal, longitudinally extending tracks 48 extending along side edges 40 on each side of floor 4. A cable 20 on each side edge 40 is secured, as in the embodiment of FIGS. 1 and 2, to act as semi-rigid bow support members for sliding movement thereon of intermediate bows 14.

Similarly, lead bow 16 is shaped like intermediate bows 14 and provided with a roller 46 on each arm 42 to roll on track 48. Lead bow 16 is secured by appropriate securing means 50 to a drive cable 22 mounted with horizontal reaches 24 parallel to cables 20. Again the lower ends 30 of lead bow 16 are slidably mounted on cables 20.

The lower ends 18 of intermediate bows 14 and lower ends 30 of lead bow 16 are rearwardly offset, as illustrated, to assist in maintaining the arms of the bow in vertical orientation.

A stop means in the form of a flange 52 is preferably secured to a portion of each of the ends 18 and 30 of the bows, to extend immediately below corresponding track 48 (FIG. 4) to prevent the bows from being lifted by wind. Otherwise, the system of FIGS. 4 and 5 operates in a fashion similar to that of FIGS. 1 to 3.

Thus it is apparent that there has been provided in accordance with the invention a tarpaulin cover system for truck trailer bodies that fully satisfies the objects, aims and advantages set forth above. While the invention has been described in conjunction with specific embodiments thereof, it is evident that many alternatives, modifications and variations will be apparent to those skilled in the art in light of the foregoing description. This system can be adapted to have a lead bow only fastened to the movable drive cable eliminating the intermediate bows, with the tarapulin being attached to the semi-ridged cable by means of rings or hook-like devices. Accordingly, it is intended to embrace all such alternatives, modifications and variations as fall within the spirit and broad scope of the invention. 

What I claim as my invention:
 1. A tarpaulin cover system for open-top flatbed truck or trailer bodies having a body front and a floor with floor sides, said system comprising:a tarpaulin having a front end anchored to said body front, and a rear end; a plurality of intermediate bows extending transversely across said body and secured at spaced locations to said tarpaulin for supporting said tarpaulin, said intermediate bows having intermediate bow ends; a lead bow secured to said rear end and having lead bow ends; longitudinally extending tracks mounted on said floor sides; said lead bow and intermediated bows each having an inverted U-shape defined by a transverse bridging central portion and two similar arms extending downwardly from said central portion and terminating in free ends, and rollers mounted on said arms at similar distances from said free ends, said rollers being supported by said tracks; and bow support means for supporting said intermediate bows and lead bow, said bow support means for reciprocating said lead bow thereby moving said tarpaulin and said intermediate bows between a covered position wherein said body is covered by said tarpaulin and an open position wherein said body is open, said bow support system including a pair of linear, semi-rigid cable members secured immovably to said body and extending longitudinally along said body, with said intermediate bow ends being slidably mounted and supported on said cable members for longitudinal movement; and separate, movable drive cable means for supporting said lead bow ends and having drive portions extending longitudinally along said body in parallel to said immovable cable means, said lead bow being fixedly secured to said movable drive cable means, whereby longitudinal movement of said movable drive cable means causes said lead bow to move for opening or closing said tarpaulin.
 2. A tarpaulin cover system according to claim 1 wherein the lead bow is additionally slidably mounted on the immovable cable means.
 3. A tarpaulin cover system according to claim 2 wherein stop means are mounted on the arms of the bows to bear against the tracks from below and thereby prevent the bows from being lifted by the wind.
 4. A tarpaulin cover system according to claim 3 wherein the stop means comprises a flange mounted on the arms of the intermediate bows, the flange positioned below the corresponding track.
 5. A tarpaulin cover system according to claim 2 wherein the end portions of the arms of the intermediate bows are rearwardly offset below the rollers, and these offset ends are slidably mounted on the immovable cable means.
 6. A tarpaulin cover system according to claim 5 wherein the end portions of the arms of the lead bows are rearwardly offset below the rollers, and these offset ends are slidably mounted on the immovable cable means. 